IBM Cognos User Manual page 141

v Your model can only have one time dimension.
If the model has more than one time dimension, the Enable time-based
partitioning check box is permanently disabled.
v Dimension calculation definitions that create calculated categories are not
supported.
You cannot use a calculated category at the time dimension level in a time-based
partitioned cube.
v Special categories created manually are supported, but the placement of these
special categories in a time-based partitioned cube depends on the type. For
example,
– Time-related special categories cannot be located in the child cubes, but are
available from the control cube.
– Regular special categories appear in the child cubes when they are initially
built, but new special categories cannot be added to child cubes during
subsequent updates.
v New regular categories may be added to the child cubes but, if they are, special
categories or links to special categories are not created.
v Category counts are supported in the primary drill-down path only if the
counted level is unique and an Activity measure is explicitly set on the Rollup
tab of the Measure property sheet.
If this setting is left as the default (all measures in the cube), at run time, some
measures will be disregarded and the count will not accurately reflect all
categories with non-zero values.
Also, the Activity measure for the category count rollup cannot be one of the
following:
– a before or after-rollup calculated measure
– an externally rolled-up measure
– another category count measure
– an allocated measure, if the allocation occurs in the same dimension as the
category count, above the counted categories level
v Category inclusion is based on the time level specified when the time-based
partitioned cube was first created.
Not all children of a category are included in each cube. Only those categories
that contain data for the given time period appear in the resulting reports.
v Support for external rollup is as follows: if the child cube has a custom view
based on the time partition level, and this custom view excludes or cloaks
categories of that level, you can open the child cube. However, the excluded
categories are not shown and the value of the time dimension root is returned as
missing (N/A or zero).
v Allocations that are performed from a level above the time-based partitioning
level are not supported. Categories can only be allocated below the time-based
partitioning level.
v Temporary cube filenames are not supported because their use can yield
incorrect results.
v Drill through is supported. However, unexpected or inconsistent results may
arise if, for example, users drill through from a time-based partitioned cube
containing data that is categorized differently among the child cubes in the
group.
v Child cubes are always published with the time-based cube. Disabling
publishing for a child cube only restricts publishing of that cube individually.
Chapter 6. Creating PowerCubes
127